Intensity non-uniformity (INU) in magnetic resonance (MR) imaging is a major issue when conducting analyses of brain structural properties. An inaccurate INU correction may result in qualitative and quantitative misinterpretations. Several INU correction methods exist, whose performance largely depend on the specific parameter settings that need to be chosen by the user. Here we addressed the q...

The first section of this paper describes a method for correcting inter-slice intensity variations in MR images. The method does not rely on a tissue model or segmentation, and is not affected by the presence of abnormalities. The second section of this work extends this technique to the correction of inter-volume intensity variations in MR images of the brain, using a characterization of bi-la...

Introduction R2 relaxometry has been established as an important technique in various quantitative MR approaches [1, 2]. In practice, transverse relaxation of H nucleus usually deviates from the ideal mono-exponential decay due to the influences of various factors such as B0 inhomogeneity [3] and slice profile imperfection [4]. Free induction decay (FID) distortion causes discrepancy between R2...

To solve the problem that a parameter search easily falls into local optimum and two-dimensional electron density profile construction error is large in process of backscatter ionogram inversion, an improved method using neighborhood-aided multistep fitting proposed. The ionospheric inversion results adjacent space are combined reconstructed by correction method. introduction auxiliary informat...

A theoretical study has been conducted on the eeects of cloud horizontal inhomogeneity on the retrieval of optical depth by remote sensing of visible reeectance. Forty-ve Landsat scenes of oceanic boundary layer clouds provide a sampling of real cloud elds, including trade cumulus, open and closed cell broken stratocumulus, and solid stratocumulus. The spherical harmonic discrete ordinate metho...

The implementation of tissue inhomogeneity correction in image-based treatment planning will improve the accuracy of radiation dose calculations for patients undergoing external-beam radiotherapy. Before the tissue inhomogeneity correction can be applied, the relationship between the computed tomography (CT) value and density must be established. This tissue characterization relationship allows...

Introduction Asymmetry between odd and even echoes generates Nyquist ghost artifact in a single-shot EPI , and further enhances multiple ghost artifacts in a segmented EPI. These ghost artifacts not only severely degrade EPI image quality, but may lead to incorrect ADC values in EPI based diffusion measurements (1). Methods currently available for odd-even-echo asymmetry compensation include on...